Steps to get it of today:
1. copying then kde-base tree from the kde overlay to my personal local overlay (the only I activate)
2. emerge -auvDN world went flawlessly
3. "systemctl restart kde" from a console was needed to experience the performant Kde-4.10.1

I think the Kde herd will move the new bug fix release in the coming hours from their overlay to official portage. There seem to be no issues. I hope everybody will have fun!

PS: Performance is like the matured stable branch Kde-4.9.x again _________________fun2gen2